Nucleotide-binding, leucine-rich replicate receptors (NLRs) perceive pathogen effectors to activate plant immunity. Biochemical mechanisms underlying plant NLR stimulation have until now remained poorly understood. We reconstituted an active complex comprising the Arabidopsis coiled-coil NLR ZAR1, the pseudokinase RKS1, uridylated protein kinase PBL2, and two’-deoxyadenosine 5′-triphosphate (dATP), demonstrating the oligomerization of the complex during immune activation. The cryo–a ZAR1 resistosome is revealed by electron microscopy construction. Besides the nucleotide-binding domain, the coiled-coil domain of ZAR1 additionally leads to resistosome pentamerization by forming an &alpha-helical barrel which interacts with the leucine-rich replicate and winged-helix domain names. Structural remodeling and fold alternating during activation release the exact N-terminal amphipathic α helix of ZAR1 to form a funnel-shaped arrangement that is required for the plasma membrane association, mobile death tripping, and disease resistance, providing clues to the biochemical role of a plant resistosome.